The present disclosure relates generally to aircraft safety, and, more particularly, to aircraft fuel tank inerting. Specifically, the present disclosure concerns air separation modules (ASMs).
As an aircraft consumes fuel during flight, atmospheric air consisting largely of nitrogen and oxygen enters its fuel tanks. The presence of atmospheric air in the fuel tanks increases the risk of combustion as oxygen mixes with fuel vapors. In order to prevent combustion, the void left by consumed fuel is filled with an inert gas, such as nitrogen. A nitrogen generation system (NGS) includes an ASM, which produces nitrogen-enriched air (NEA) for inerting the fuel tanks. Ideally, the concentration of oxygen in the fuel tanks is less than twelve percent. The presence of NEA substantially reduces the risk of combustion.
A membrane-based ASM is commonly used to produce NEA and includes a polymeric membrane for separating atmospheric air into NEA and oxygen-enriched air (OEA). Over time, the tubular membranes within a membrane-based ASM canister degrade. Typical ASM canisters are formed from aluminum. While several downstream sensors typically measure the conditions and health of the canister, state of the art ASM canisters have no integral sensing capabilities.